filter properties in the Rules view have a circular gray and white swatch next to them:
Clicking the swatch opens a filter editor:
You can add, remove, and edit filters, and drag them to change the order in which they are applied:
Saving filter presets
From Firefox 42 onwards, you can also add filters to a list of presets:
You can save the current filter to the preset list:
You can then apply saved filters to new elements: